91暗网

Kelly Sheppard

Professor of Chemistry

Office: BTCIS 210D
Phone: 518-580-5135
Email: ksheppar@skidmore.edu

At 91暗网 since 2010

Education

A.B. 1999, Occidental College
Ph.D. 2007, Yale University
Postdoctoral Associate, 2007-2010, Yale University

Research

Research Lab: BTCIS 207 - Kal Das Biomolecular Research Suite
My is interested in the different pathways organisms use to translate the genetic code, in particular with regard to the amino acid asparagine (Asn). To translate Asn codons requires forming the adapter molecule asparaginyl-transfer RNA (Asn-tRNA), a step essential for all of life. In nature, two distinct routes have evolved to form this vital adapter molecule.

A number of bacteria, including known human pathogens, appear to encode both routes. Informed by advances in biochemistry, molecular genetics, microbiology, and molecular evolution, we are interested in determining if this is the case and if so how these organisms use both pathways.

The work provides insight not only into the life cycles of these bacteria but also into the evolution of the Asn decoding pathways. The research also lays the foundation for development of new antibiotics to target these pathogenic bacteria. We are also applying our knowledge of these pathways to expand the genetic code to incorporate unnatural amino acids into proteins to facilitate studies on Alzheimer鈥檚 Disease and more active anti-cancer agents.

Student collaborators gain expertise in molecular subcloning, PCR, protein overproduction and purification, plasmid mini/maxi-preparations, E. coli complementation studies, chromatography, gel electrophoresis, enzyme kinetics, buffer and reagent preparation, sequence analysis, and in vitro transcription as well as learn how to handle DNA, RNA, and proteins appropriately.

The work has been supported by grants from the National Science Foundation and Research Corporation. Students have the opportunity to present their research at regional, national, and international meetings as well as publish in peer-reviewed journals.

Courses

• (lecture and lab; fulfills Scientific Inquiry through Practice and Applied Quantitative Reasoning requirements)
• (lecture and lab)
• /
• (fulfills Bridge Experience requirement)
• SSP 100 Scribner Seminar-Coming of Age:Food, Drugs and Sex after the Biotech Revolution

Selected Publications (*authors contributed equally to this work; 91暗网 Undergraduates are underlined)

• Lewis, A.M., Fallon, T., Dittemore, G.A., and Sheppard, K. (2024) . IUBMB Life, DOI: 10.1002/iub.2811. 
• Kennerly, W.W., Frederick, K.A., and Sheppard, K. (2020) J. Chem. Ed., 97, 1295-1302.
• Nair, N., Raff, H., Islam, M.T., Feen, M., Garofalo, D.M., and Sheppard, K. (2016) The Bacillus subtilis and Bacillus halodurans aspartyl-tRNA synthetases retain recognition of tRNA^Asn. J. Mol. Biol. 428, 618-630.
• Suzuki, T., Nakamura, A., Kato, K., S枚ll, D., Tanaka, I., Sheppard, K., and Yao, M. (2015) Structure of the Pseudomonas aeruginosa transamidosome reveals unique aspects of bacterial tRNA-dependent asparagine biosynthesis. Proc. Nat. Acad. Sci. U.S.A. 112, 382-387.
• Alperstein, A., Ulrich, B., Garofalo, D.M., Dreisbach, R., Raff, H., and Sheppard, K. (2014) The predatory bacterium Bdellovibrio bacteriovorus aspartyl-tRNA synthetase recognizes tRNA^Asn as a substrate. PLoS ONE 9(10): e110842.
• Mladenova, S.R., Stein, K.R., Bartlett, L., and Sheppard, K. (2014) Relaxed tRNA specificity of the Staphylococcus aureus aspartyl-tRNA synthetase enables RNA-dependent asparagine biosynthesis. FEBS Lett. 588, 1808-1812.
• O'Donoghue, P., Sheppard, K., Nureki, O., and S枚ll, D. (2011) Rational design of an evolutionary precursor of glutaminyl-tRNA synthetase. Proc. Natl. Acad. Sci. U.S.A. 108, 20485-20490.
• Englert, M., Sheppard, K., Aslanian, A., Yates III, J., and S枚ll, D. (2011) Archaeal 3'-phosphate RNA splicing ligase characterization identifies the missing component in tRNA maturation. Proc. Natl. Acad. Sci. U.S.A. 108, 1290-1295.
• Englert, M., Sheppard, K., Gundllapalli, S., Beier, H., and S枚ll, D. (2010) Branchiostoma floridae has separate healing and sealing enzymes for 5'-phosphate RNA ligation. Proc. Natl. Acad. Sci. U.S.A. 107, 16834-16839.
• Rampias, T.*, Sheppard K.*, and S枚ll, D. (2010) The archaeal transamidosome for RNA-dependent glutamine biosynthesis. Nucleic Acids Res. 38, 5774-5783.

Affiliations

American Association for the Advancement of Science
American Chemical Society
American Society for Biochemistry and Molecular Biology
American Society for Microbiology
Council on Undergraduate Research
New York Academy of Sciences